CVE-2026-55759: Rocketchat Rocket.chat

High severity, CVSS 7.4. EPSS: 0.3% chance of exploitation in the next 30 days.

Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13, Rocket.Chat's Apple Sign-In handler verifies JWT signatures but skips claims validation. Any Apple-signed JWT with a non-empty iss is accepted regardless of aud, exp, nbf, or nonce. An attacker who obtains a target user's Apple identity token (from server logs, an intercepted sign-in flow, or another application sharing the same Apple developer team) can replay it to authenticate as that user, with no expiration on the replay window. This vulnerability is fixed in 8.5.1, 8.4.4, 8.3.6, 8.2.6, 8.1.6, 8.0.7, and 7.10.13.

Affected products

• Rocketchat Rocket.chat: from 8.5.0-rc.0, before 8.5.1 (fixed in 8.5.1); from 8.4.0-rc.0, before 8.4.4 (fixed in 8.4.4); from 8.3.0-rc.0, before 8.3.6 (fixed in 8.3.6); from 8.2.0-rc.0, before 8.2.6 (fixed in 8.2.6); from 8.1.0-rc.0, before 8.1.6 (fixed in 8.1.6); from 7.11.0-rc.0, before 8.0.7 (fixed in 8.0.7); …

Published 2026-06-24. Last modified 2026-06-26.